Benthic dredge construction

ABSTRACT

A dredge especially adapted for taking samples from the bottom of a body of water comprises a hollow body open at its top and bottom, but provided at both its top and its bottom with closures movable between open and closed positions and biased to their closed positions. The top and bottom closures are equipped with means for latching the closures in their open positions. A latch release mechanism is provided for effecting release of the closure latch members so as to enable the closures to move from their open positions to their closed positions.

United States Patent 1 Wetherbee 1 1 Oct. 2, 1973 [54] BENTHIC DREDGE CONSTRUCTION 3,036,393 5/1962 Baird, Jr. l 37/184 2,242,940 5 1941 C l' 37 184 ['75] lnventor: Thomas J. Wetherbee, Saginaw, I am I c Primary Examiner-Robert E. Pulfrey 1 1 Asslgneel PP Corporatiun, Sagmaw, Assistant ExaminerEugene H. Eickholt Mlch- AttorneyJohn F. Learman et a1.

[22] Filed: June 5, 1972 21 Appl. No.: 259,425 1571 ABSTRACT A dredge especially adapted for taking samples from the bottom of a body of water comprises a hollow body open at its top and bottom, but provided at both its top and its bottom with closures movable between open and closed positions and biased to their closed positions. The top and bottom closures are equipped with means for latching the closures in their open positions. A latch release mechanism is provided for effecting release of the closure latch members so as to enable the closures to move from their open positions to their closed positions.

11 Claims, 3 Drawing Figures BENTIIIC DRED GE CONSTRUCTION The invention disclosed herein relates to a dredge of the kind especially adapted for taking samples from the bottom of a body of water, and more particularly the invention pertains to a benthic sampling dredge having top and bottom closures which may be operated remotely so as to move from normally open positions to closed positions.

Bottom sampling dredges of the kind to which the invention relates have been in wide usage for many years. Conventionally, such a dredge has a hollow body open at both its upper and lower ends. Pivoted on the body is a pair of clamshell closures which are spring biased toward a position in which they close the bottom of the body and which, in the act of closing, cut a sample of the bottom of the body of water and support the sample within the body. A conventional dredge is provided with means for releasably latching the clamshell closures in their open positions, and such latch means may be operated from the surface of the body of water in such manner as to effect release of the clamshells and movement thereof to their closed positions after the sampler has been lowered to the bottom.

A conventional sampling dredge also has closure doors hinged to the body adjacent the upper end thereof. Such doors normally have no biasing means associated therewith, but instead, are freely swingable between open and closed positions. In theory, lowering of such a sampling dredge through a body of water with its clamshell closures in the open position will result in the upper closure doors being maintained in their open positions by the movement of the dredge through the water. In practice, however, the upper closure doors often fail to move to their fully open positions, whereupon the closure doors act as vanes or fins and result in erratic movements of the dredge as it passes through the water. When the dredge moves through the water in an erratic manner, it is impossible for the operator to determine accurately the exact area from which the sample is taken.

Another disadvantage of a sample dredge having freely swingable upper closure doors is that one or both of such doors sometimes may be incapable of closing fully due to sticking of the hinges. In such a ease, upward movement of the dredge through the water may cause the sample to be disturbed or washed out of the dredge.

An object of this invention is to provide a benthic dredge for taking a sample from the bottom of a body of water and which is constructed in such manner as to overcome the undesirable characteristics referred to above.

Another object of the invention is to provide a bottom sampling dredge having upper closure doors constantly biased to their closed positions, and provided with releasable latching means for maintaining the doors open until such time as they are deliberately closed.

A further object of the invention is to provide a dredge of the character described and in which the upper end closure doors may be released simultaneously for movement to their closed positions.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawing, in which:

FIG. 1 is a side elevational view, partly in section, of a benthic sampling dredge constructed in accordance with the invention;

FIG. 2 is an end elevational view of the dredge; and

FIG. 3 is a top plan view of the dredge.

A dredge constructed in accordance with the invention comprises a hollow body 1 composed of parallel side walls 2 and 3 and parallel end walls 4 and 5. The body 1 is open at both its top and its bottom.

Fixed to the outer surfaces of the side walls 2 and 3 is a pair of posts 6. Pivoted on the posts 6 is a pair of clamshell closures 7 and 8 of conventional construction, the closure 7 having a pair of arms 9 which straddle the body and are joined at their outer ends by an arcuate web 10. The closure 8 also has a similar pair of arms 11 joined by an arcuate web 12. Wound around either or both of the posts 6 is a powerful torsion spring 13 having legs 14 and 15 which bear against studs 16 and 17, carried by the arms 9 and 11, respectively. The spring 13 constantly biases both of the closures 7 and 8 to their closed positions indicated in chain lines in FIG. 1. In their closed positions, the arms 9 and 11 overlap one another and the confronting edges of the webs l0 and 12 abut one another so as to form a closure for the bottom of the body 1.

At the upper end of the body 1 is a pair of closure doors l8 and 19 which are hinged to the opposite side walls 2 and 3 by means of hinges 20. The length of each door preferably is somewhat greater than the corresponding dimension of the body 1 so that the ends of the doors overhang the end walls 4 and 5. The width of each door preferably is greater than half the corresponding dimension of the body so that, in their closed positions, the doors overlap one another as is indicated in dotted lines in'FIG. 2.

A bail 21 having a pair of legs 22 depending from a horizontal bight 23 is carried by the body I, the free ends of the legs 22 being secured to the outer surfaces of the body walls 2 and 3 by nut and bolt assemblies 24. The bight 23 projects a sufficient distance above the upper end of the body to enable the doors l8 and 19 to be swung upwardly to their open positions, as is indicated in full lines in FIGS. 1 and 2.

A latch release mechanism 25 is carried by the bail 21 and comprises a bracket 26 welded or otherwise fixed to the bight 23 and supporting an upstanding post 27. Slidably fitted on the post 27 is an operating bar 28 which carries at its opposite ends a pair of J-shaped members 29 which pass through openings in the bracket 26 and terminate in upstanding retaining legs 30. Pins 31 span the openings in the bracket 26 for reception in the crook of each of the members 29, and the pins 31 are so located that, when the bar 28 is in its uppermost position, the free ends 30 of the members 29 occupy a projected position above the bracket 26.

A compression spring 32 reacts between the bracket 26 and the bar 28 so as constantly to urge the latter to its uppermost position. The spring is yieldable, however, so as to enable the bar 28 to be displaced toward the bracket 26 a distance sufficient to permit the legs 30 to be retracted or positioned below the level of the upper surfaces of the bracket 26.

Latching means 33 is provided for releasably latching the clamshell closures 7 and 8 in their open positions and comprises a pair of flexible cables 34 and 35, one end of the cable 34 being anchored to a stud 36 carried by the web 10 of the member 7 and the corresponding end of the cable 35 being anchored to a similar stud 37 carried by the web 12. The opposite end of the cable 34 has a coupling loop 38 adapted to receive one of the retaining legs and the corresponding end of the cable has a similar coupling loop 39 adapted to accommodate the other retaining leg 30. The length of each of cables 34 and 35 is such that, when their respective loops 38 and 39 receive the retaining legs 30, the clamshell closures 37 and 38 are maintained in their open positions. Ball-like enlargements 40 and 41 are fixed to the respective cables 34 and 35 to facilitate their connection to the retaining legs 30, and the cables 34 and 35 pass through apertured guide pins 42 and 43, respectively, carried by the end walls 4 and 5 of the body.

As thus far described, the dredge is conventional and the structural details of the dredge form no part of the invention except insofar as they cooperate with the structure hereinafter to be described.

Each of the upper closure doors l8 and 19 is acted upon by a spring device 44 which constantly biases the associated door to its closed position. Each spring device 44 may constitute any one of a number of known spring constructions, but as disclosed each such device comprises a U-shaped member having a base 45 which is riveted or otherwise suitably fixed to the associated side wall 2 or 3 and from which extends a pair of contoured spring arms 46 which overlie and bear against the associated door 18 or 19. The spring devices 44 normally occupy the positions shown in chain lines in FIG. 2, but are capable of being flexed to the full line positions shown in FIGS. 1 and 2 when the doors 18 and 19 are moved from their closed positions to their open positions.

Means for latching the doors l8 and 19 in their open positions comprises a pair of flexible cables 47 and 48. One end of the cable 47 is anchored to a post 49 carried by the door 18 and the corresponding end of the cable 48 is anchored to a post 50 carried by the door 19. The opposite end of the cable 47 has a coupling loop 51 adapted to accommodate one of the retaining legs 30 and the opposite end of the cable 48 has a similar coupling loop 52 adapted to accommodate the other retaining leg 30. The cables 47 and 48 are of such length that, when the respective doors l8 and 19 are moved to their open positions, the loops 51 and 52 may pass around the associated bail legs 22 for accommodation of the respective retaining legs 30 so as to maintain the doors in their open positions.

To condition the apparatus for operation, the operator from a position at the surface of a body of water may latch the clamshell closures 7 and 8 in their open positions by connecting the cables 34 and 35 to their respective retaining legs 30. The operator then may move the doors l8 and 19 to their open positions, against the bias of the springs 44, and latch the doors in their open positions by connecting the cables 47 and 48 to the respective legs 30. The dredge then may be lowered through the body of water by means of a line or cable 53. Since the closure members at both the upper and lower ends of the dredge body 1 are positively maintained in their open positions, the vertical movement of the dredge through the water will not be subjected to erratic movements due to variations in the positions of the doors l8 and 19. As a consequence, the operator will be able to identify the area from which a sample is to be taken.

When the dredge reaches the bottom of the body of water, its lower end may be embedded in the sediment. A heavy weight or messenger 54 which encircles the cable 53 may be dropped so as to strike the operating bar 28 and displace it downwardly a distance sufficient to cause the retaining legs 30 to move to a position below the upper surface of the bracket 26. The loops of the latch cables 34, 35 and 47, 48 thus will be released by the latch legs so as to enable the springs 13 and 44 to move the clamshell and upper closures, respectively, to their closed positions. A sample of the bottom of the body of water thus will be enclosed within the dredge body. The dredge may be retrieved by the operator via the cable 53 and during upward movement of the dredge the doors 18 and 19 will be maintained in their closed positions by the springs 44.

The disclosed embodiment is representative of the presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.

What is claimed is:

l. A dredge construction comprising a hollow body having an open bottom and an open top; means carried by said body for closing the bottom thereof; closure means for closing the top of said body; means mounting said closure means at the top of said body for movements between closed and open positions; latch means connected to said closure means and operable to maintain said closure means in said open position; and means engageable with said latch means for releasing said latch means whereby said closure means is movable from said open position to said closed position.

2. A dredge according to claim 1 including spring means acting on said closuremeans and biasing the latter toward said closed position.

3. A dredge according to claim 1 wherein said closure means comprises a pair of doors one of which is of such size as to overlie substantially one-half the top of said housing and the other of which is of such size as to overlie the remainder of the top of said housing.

4. A dredge according to claim 3 wherein said doors are of such size as to overlap one another when said doors are in their closed position.

5. A dredge according to claim 1 wherein said latch means comprises flexible means anchored at one end to said closure means and having coupling means at its other end; and releasable retaining means carried by said body, said coupling means being engageable with and disengageable from said retaining means.

6. A dredge according to claim 5 wherein said retaining means comprises a movable leg and wherein said coupling means comprises a loop of such size as to accommodate said leg.

7. A dredge according to claim 6 including spring means acting on said leg and biasing the latter to a projected position, and operating means connected to said leg for moving the latter from its projected position to a retracted position.

8. A dredge for taking a sample from the bottom of a body of water, said dredge comprising a hollow body having an open bottom and an open top; a pair of clamshell members mounted on said body for movement from a first position in which the bottom of said body is open to a second position in which said members close the bottom of said body; spring meansacting on said clamshell members and urging the latter to said second position; a first pair of latch members connected at corresponding ends to the respective clamshell members and having first coupling means at their opposite ends; releasable retainer means carried by said body for engagement with and disengagement from said coupling means whereby said spring means is selectively disabled from and enabled to move said clamshell members to said second position; a pair of door members mounted on said body for movement from a first position in which the top of said body is open to a second position in which the top of said body is closed; a second pair of latching members connected at corresponding ends to the respective door members and having second coupling means at their opposite ends engageable with and disengageable from said retaining means for selectively disabling and enabling to said retaining means for moving the latter between positions in which said retaining means is and is not engageable with said first and second coupling means.

9. A dredge according to claim 8 including spring means acting on said door members and biasing them to said second position.

10. A dredge according to claim 8 wherein said retaining means comprises a pair of legs and wherein each of said coupling means comprises a loop at said opposite end of its respective latch member of such size as to accommodate one of said legs.

11. A dredge according to claim 10 wherein each of said legs is accommodated in a pair of said loops when said clamshell members and said door members are in their respective first positions. 

1. A dredge construction comprising a hollow body having an open bottom and an open top; means carried by said body for closing the bottom thereof; closure means for closing the top of said body; means mounting said closure means at the top of said body for movements between closed and open positions; latch means connected to said closure means and operable to maintain said closure means in said open position; and means engageable with said latch means for releasing said latch means whereby said closure means is movable from said open position to said closed position.
 2. A dredge according to claim 1 including spring means acting on said closure means and biasing the latter toward said closed position.
 3. A dredge according to claim 1 wherein said closure means comprises a pair of doors one of which is of such size as to overlie substantially one-half the top of said housing and the other of which is of such size as to overlie the remainder of the top of said housing.
 4. A dredge according to claim 3 wherein said doors are of such size as to overlap one another when said doors are in their closed position.
 5. A dredge according to claim 1 wherein said latch means comprises flexible means anchored at one end to said closure means and having coupling means at its other end; and releasable retaining means carried by said body, said coupling means being engageable with and disengageable from said retaining means.
 6. A dredge according to claim 5 wherein said retaining means comprises a movable leg and wherein said coupling means comprises a loop of such size as to accommodate said leg.
 7. A dredge according to claim 6 including spring means acting on said leg and biasing the latter to a projected position, and operating means connected to said leg for moving the latter from its projected position to a retracted position.
 8. A dredge for taking a sample from the bottom of a body of water, said dredge comprising a hollow body having an open bottom and an open top; a pair of clamshell members mounted on said body for movement from a first position in which the bottom of said body is open to a second position in which said members close the bottom of said body; spring means acting on said clamshell members and urging the latter to said second position; a first pair of latch members connected at corresponding ends to the respective clamshell members and having first coupling means at their opposite ends; releasable retainer means carried by said body for engagement with and disengagement from said coupling means whereby said spring means is selectively disabled from and enabled to move said clamshell members to said second position; a pair of door members mounted on said body for movement from a first position in which the top of said body is open to a second position in which the top of said body is closed; a second pair of latching members connected at corresponding ends to the respective door members and having second coupling means at their opposite ends engageable with and disengageable from said retaining means for selectively disabling and enabling said door members to move from said first position to said second position; and operating means connected to said retaining means for moving the latter between positions in which said retaining means is and is not engageable with said first and second coupling means.
 9. A dredge according to claim 8 including spring means acting on said door members and biasing them to said second position.
 10. A dredge according to claim 8 wherein said retaining means comprises a pair of legs and wherein each of said coupling means comprises a loop at said opposite end of its respective latch member of such size as to accommodate one of said legs.
 11. A dredge according to claim 10 wherein each of said legs is accommodated in a pair of said loops when said clamshell members and said door members are in their respective first positions. 